1. Field of the Invention
This invention relates to a method of making a one-piece elevator link having a shank, an eye at one end of the shank, and another eye at the other end of the shank. Such elevator links are employed in matched pairs to suspend a pipe elevator from the block hook of an oil well drilling rig. The invention also relates to a cast elevator link blank.
2. Description of the Prior Art
Heretofore, weldless elevator links have been made in accordance with the manufacturing method described in U.S. Pat. No. 1,756,376, issued Apr. 29, 1930, to G. W. Moore, for "Method of Making Weldless Elevator Links." This known method involves rolling or forging a bar of uniform cross-sectional diameter into a section of reduced central diameter, both ends remaining the same dimension in cross section as the original bar, then flattening both ends, then cutting apertures in both ends to form eyes. In practice, after the apertures have been cut, the eyes and limited adjacent shank sections are forged in an open forging die to render them into final form. Finally, the flashing and irregularities are removed and the links are heat treated, quenched, and matched in sets so that the two links of each set are substantially equal in length.
In applicant's prior U.S. Pat. No. 3,461,666 issued Aug. 19, 1969, for "Elevator Link and Process of Making the Same", one of the elevator links shown in the drawings is fabricated by bending a metal bar having a grain structure substantially parallel to the axis of the bar into an elongated ring having generally parallel side sections spaced from each other at opposite ends to provide openings, and adjacent to each other intermediate the openings to provide a shank portion, in which the ends of the bar are substantially butted together in the shank portion; applying weld metal to the ends of the bar to join the ends together; and applying additional weld metal, adjacent to and including the weld metal applied to the ends of the bar, for joining the side sections together in the shank portion. After the welding has been completed, the shank portion of the link may be forged to reduce its cross-sectional area and elongate it, whereby to orient the grain structure of the weld metal in the direction of elongation. The other elevator link illustrated in the drawings is similar, but is made from two pieces of metal bars.